A group of U.S. scientists found that several species of mammals that only eat meat have evolved to lose their ability to taste things that are sweet, Science Daily reported Monday.

In a previous study, researchers from Monell Chemical Senses Center found that domestic and wild cats, which live exclusively on meat, are unable to taste sweet compounds to genetic defects.

To determine if their diet was related to loss of taste, the Monell team then examined the sweet taste receptor genes from 12 related mammalian species with varying dietary habits.

They found that taste loss was widespread among meat-eating species.

Sea lion, fur seal, Pacific harbor seal, Asian otter, spotted hyena, fossa, and banded lingsang, exclusive meat-eaters, all had defective sweet receptor genes.

Further study showed that these seven species vary in how badly their sweet senses were defected.

However, the Aardwolf, Canadian otter, spectacled bear, raccoon, and red wolf, a group which consists of exclusive meat-eaters and omnivores, were all able to taste sweet. This indicates that eating meat does not always lead to sweet taste loss.

To find more about the relationship between diet and taste function, team examined the umami (savory) taste receptor genes in the sea lion and bottlenose dolphin.

Since these mammals swallow their food whole, it can be speculated that taste is not very important to their diet choice.

They found that the weet and umami receptor genes were non-functional in both.

The study suggests that diet-related taste loss has happened throughout evolution.

“Different animals live in different sensory worlds and this particularly applies to their worlds of food. Our findings provide further evidence that what animals like to eat -- and this includes humans -- is dependent to a significant degree on their basic taste receptor biology,” said Gary Beauchamp, the senior author of the study.


By Yoon Min-sik